ukulele scale
C major
C1D2E3F4G5A6B7
The seven-note scale everything else is measured against: two whole steps, a half, three whole steps, a half.
Written out
Every accidental is written in, rather than left to a key signature, so the letters can be read one at a time.
The step pattern
CWDWEHFWGWAWBHC
What is true of it
C major is C, D, E, F, G, A and B, and back to C.
Its steps are W – W – H – W – W – W – H, where W is a whole step and H a half.
It uses no sharps and no flats at all: seven letters, seven white keys.
On the same tonic, C melodic minor differs from it by exactly one note.
Across the first twelve frets of the ukulele its notes fall in 32 places, which is what makes a scale a shape rather than a list.
Chords made only of these notes
Found by testing every chord in the catalogue against these 7 sounds, not chosen.